Wearable devices such as glasses and watches come in many forms, but have limited space for circuitry and power. Nevertheless, the form factor and habitual use of wearable products provide benefits separate from targeted single function devices. Because of this, wearable devices such as wristbands, glasses, and other such devices with limited form factors continue to include additional functionality. Even so, limits in space and power resources drive continual innovation in the wearable device space.